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Color is a straightforward way to make those boring QR codes special. This seems to have caught on with quite a few people, as a quick Google image search reveals. But, there’s a problem. Deviating from the ideal black-and-white makes the QR code more difficult to scan. In this article, I show a way to… read more

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After the fun with the “doctored” photo from a previous article, I thought it would be nice to show another example of a photo that “fades to gray” if you’re not careful. This time the image disappears if it is converted to grayscale in the wrong way. This is… read more

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This guy was really going for it, jumping from the falls in the Krka National Park. He did it a few times, so I had time to choose my position for this photo. It looked as if he was jumping straight into the frothy water at the bottom, although he probably knew what he was doing… read more

You have probably already encountered a few QR codes. These codes are becoming more and more common, and can be found on business cards, ads, historical buildings, T-shirts, etc. You're meant to scan them using your smartphone. They can contain all sorts of information, the most common being plain text, URLs, and contact information. The information is… [This article contains a demo in which you can create your own QR codes!]read more

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This article points out the danger of assuming that astronomical images are encoded using linear intensity. It is meant for the many people that are performing astronomical observations using regular cameras. Not because there’s something wrong with that, but because those cameras are optimized for “normal” photography and video, not for numerical calculations on their images. The illustration below… read more

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The distance between two points is a concept that is, in every day use, clear and unambiguous. Mathematically, the normal (every day) distance between two points is called the Euclidean distance, but mathematicians generalize this definition. I show how, and I try to make you think by showing how circles look using some of these alternative definitions… read more